common/Utils/UserAccessCtrl/Appsettings.cs

using System;
using System.Configuration;
using System.IO;
using System.Linq;
using System.Runtime.CompilerServices;
using System.Windows.Forms;

namespace Xylem.Common.Utils.UserAccessCtrl
{
    public static class Appsettings
    {
        private const String EMPTY = "";
        private const String SETTINGS_SECTION = "appSettings";
        private static Configuration configuration 
            = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
        private static KeyValueConfigurationCollection settings
            = configuration.AppSettings.Settings;

        public static String WorkingDirectory
        {
            get
            {
                try
                {
                    return Directory
                        .GetParent(configuration.FilePath)
                        .FullName;
                }
                catch
                {
                    return ".";
                }
            }
        }

        public static Int16 GMHPort
        {
            get => GetInt16();
            set => SetValue(value);
        }


        public static Int32 MessurementDauer
        {
            get => GetInt32();
            set => SetValue(value);
        }

        public static Int32 MessurementStep
        {
            get => GetInt32();
            set => SetValue(value);
        }

        public static String GetKey(String key)
        {
            var _key = settings.AllKeys.FirstOrDefault(x => x.Equals(key, StringComparison.OrdinalIgnoreCase));

            if (string.IsNullOrWhiteSpace(_key))
            {
                _key = key;

                settings.Add(_key, string.Empty);
            }

            return _key;
        }

        private static String GetValue([CallerMemberName] String property = EMPTY) 
            => settings[property]?.Value?.ToString() ?? string.Empty;

        private static Int16 GetInt16([CallerMemberName] String property = EMPTY)
        {
            var value = GetValue(property);

            if (short.TryParse(value, out var result))
            {
                return result;
            }

            return default(Int16);
        }

        private static Int32 GetInt32([CallerMemberName] String property = EMPTY)
        {
            var value = GetValue(property);

            if (int.TryParse(value, out var result))
            {
                return result;
            }

            return default(Int16);
        }

        private static void SetValue<T>(this T value, [CallerMemberName] String property = EMPTY)
        {
            var key = GetKey(property);
            
            settings[key].Value = value?.ToString() ?? EMPTY;
        }

        public static void SaveSettings()
        {
            configuration.Save(ConfigurationSaveMode.Full);
            ConfigurationManager.RefreshSection(SETTINGS_SECTION);

            configuration = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
            settings = configuration.AppSettings.Settings;
        }
    }
}